Method and system for additive-ablative fabrication

ABSTRACT

A printer pressing assembly for forming material layers is provided. The printer pressing assembly includes a support assembly having a support surface, a driver and a press stop. The driver is able to change an elevation of the support surface relative to an elevation of the press stop. A nozzle is capable of dispensing a material onto the support surface. Further, a press is positionable opposite to the support surface and capable of moving relative to the support. Additionally, the press stop is capable of being elevated above the support surface so as to engage an abutment surface of the press to set a pre-determined distance between the contact surface of the press and the support surface.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation application of U.S. application Ser. No.16/126,565, filed on Sep. 10, 2018, which is a divisional application ofU.S. application Ser. No. 15/704,575, filed on Sep. 14, 2017 and nowU.S. Pat. No. 10,099,422 issued on Oct. 16, 2018, which claims thebenefit of U.S. Provisional Application No. 62/394,849 filed on Sep. 15,2016. The contents of each of the above-mentioned applications arehereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present disclosure, in some embodiments thereof, relates to solidfree form fabrication (SFF) and, more particularly, but not exclusively,to a method, system and apparatus for SFF by an additive-ablativeprocess.

BACKGROUND OF THE INVENTION

SFF is typically used in design-related fields where it is used forvisualization, demonstration and mechanical prototyping. Thus, inthree-dimensional fabrication facilitates rapid fabrication offunctioning prototypes with minimal investment in tooling and labor maybe employed. Such rapid prototyping shortens the product developmentcycle and improves the design process by providing rapid and effectivefeedback to the designer. Three-dimensional fabrication can also be usedfor rapid fabrication of non-functional parts, e.g., for the purpose ofassessing various aspects of a design such as aesthetics, fit, assemblyand the like. Additionally, three-dimensional fabrication techniqueshave been proven to be useful in the fields of medicine, where expectedoutcomes are modeled prior to performing procedures. It is recognizedthat many other areas can benefit from rapid prototyping technology,including, without limitation, the fields of architecture, dentistry andplastic surgery where the visualization of a particular design and/orfunction is useful.

Over the past decade, there has been considerable interest in developingcomputerized three-dimensional fabrication techniques.

In one such technique, see, e.g., U.S. Pat. No. 6,259,962, a material isdispensed from a printing head having a set of nozzles to deposit layerson a supporting structure. The layers are then cured using a suitablecuring device. It is further noted that in the conventional art printingviscous material with a resolution below 40 μm is relatively complex.

Additionally, the conventional art has a problem of oxygen inhibitionthat may occur in, for example, the curing of a monomer. In this regard,oxygen inhibition may hinder significantly or can even stop the curingprocess. For this reason, it is relatively complex to cure plastic inatmospheric environment; and therefore, a special inert gas environmentis required.

Molecular oxygen can physically quench the triplet state of thephoto-initiator/sensitizer, or it can attract free radicals or activeradical centers and transform them into unreactive peroxide radicals.The end result may range from reduced coating properties to uncured,liquid surfaces on the coating. The aforementioned problem is even morepronounced in low intensity curing processes, such as UV LED or UVAcure, which frequently result in sticky, uncured surfaces.

In another technique, see, e.g., in U.S. Pat. No. 5,204,055, a componentis produced by spreading powder in a layer and then depositing a bindermaterial at specific regions of a layer as determined by the computermodel of the component. The binder material binds the powder both withinthe layer and between adjacent layers. In a modification of thisapproach, the powder is raster-scanned with a high-power laser beamwhich fuses the powder material together. Areas not hit by the laserbeam remain loose and fall from the part upon its removal from thesystem.

In an additional technique, see, e.g., in U.S. Pat. No. 4,575,330, afocused ultra-violet (UV) laser scans the top of a bath of aphotopolymerizable liquid material. The UV laser causes the bath topolymerize where the laser beam strikes the surface of the bath,resulting in the creation of a solid plastic layer just below thesurface. The solid layer is then lowered into the bath and the processis repeated for the generation of the next layer, until a plurality ofsuperimposed layers forming the desired part is obtained.

SUMMARY OF THE INVENTION

Some embodiments of the present disclosure provide a method and systemfor SFF that combine additive manufacturing and selective ablation. Theadditive manufacturing is preferably at a lower resolution compared tothe selective ablation. An advantage of the technique of the presentembodiments is that it optionally and preferably provides an improvedresolution and/or improved fabrication speed. When the ablation is by alaser beam, it can provide a lateral resolution of less than 16 μm, morepreferably less than 8 μm, more preferably less than 4 μm, morepreferably less than 2 μm, e.g., 1 μm or less. The wavelength of thelaser light can optionally and preferably be set to define an absorptiondepth, hence also a vertical resolution (minimal layer thickness) thatis approximately an order of magnitude less than the lateral resolution(e.g., less than 0.16 μm, more preferably less than 0.8 μm, morepreferably less than 0.4 μm, more preferably less than 0.2 μm, e.g.,about 0.1 μm or less). In some embodiments of the present disclosure thelaser light has a wavelength in an ultraviolet range, e.g., from about300 nm to about 400 nm, for example, about 355 nm. Ultraviolet laser isadvantageous from the standpoint of performances. However, for lowerresolution, and for materials that do not require ultraviolet light forablation, the laser can be in the infrared range. Infrared laser isadvantageous from the standpoint of cost and beam manipulationsimplification.

Another advantage of the technique of the present embodiments is that itallows the use of a variety of types of building materials, since it issufficient to execute the additive manufacturing at relatively lowlateral resolution. The present embodiments are suitable for SFF ofthree-dimensional (3D) objects from low viscosity materials (e.g.,photoresists or the like) to high viscosity materials (e.g., glue,conductive paste or the like). Representative examples of materialfamilies suitable for the present embodiments including, withoutlimitation, ceramic materials, metals, silica, plastics and wax. Anotheradvantage of the technique of the present embodiments is that it allowsfabrication 3D objects from a multiplicity of materials. In particular,the present embodiments can be used to fabricate electrically conductivepatterns.

Another advantage of the technique of the present embodiments is that itcan be combined with an embedding technique, wherein a foreign element,such as, but not limited to, an electronic device, is embedded in thefabricated 3D object. Unlike conventional SFF systems in which thefabrication is typically within a working chamber, the SFF process ofthe present embodiments is optionally and preferably performed at anopen space, thus allowing embedding the foreign element in situ. Forexample, the present embodiments contemplate an automatic process inwhich a robotic arm or the like embeds the foreign element in one ormore of the layers of the 3D object without removing the 3D object fromthe SFF working surface.

Thus, according to an aspect of some embodiments of the presentdisclosure there is provided a method of solid free form fabrication(SFF). The method comprises: receiving SFF data collectively pertainingto a three-dimensional shape of the object and comprising a plurality ofslice data each defining a layer of the object. The method alsocomprises, for each of at least a few of the layers, dispensing abuilding material on a receiving medium, straightening the buildingmaterial, and selectively ablating the building material according torespective slice data.

According to some embodiments of the present disclosure, the methodcomprises dispensing at least one additional building material onto thebuilding material to fill vacant regions formed in the layer by theselective ablation, and straightening the additional building material,wherein a resolution of the dispensing of the additional buildingmaterial is less than a resolution of the selective ablation.

According to some embodiments of the present disclosure, the dispensingof the building material and the additional building material providethe same lateral coverage.

According to some embodiments of the present disclosure, the dispensingof the building material is to cover a layer immediately below the layerby its entirety.

According to some embodiments of the present disclosure, the dispensingof the building material is selective, wherein a resolution of thedispensing of the building material is less than a resolution of theselective ablation.

According to some embodiments of the present disclosure, the dispensingof the additional building material is selective.

According to some embodiments of the present disclosure, the buildingmaterial is curable, and the method comprises at least partially curingthe building material after the ablation. According to some embodimentsof the present disclosure the building material is curable, and themethod comprises at least partially curing the building material priorto the ablation. According to some embodiments of the presentdisclosure, the additional building material is curable, and the methodcomprises at least partially curing the additional building material.

According to some embodiments of the present disclosure, the ablation isby an ablation system, wherein the curing is also by same ablationsystem except operating at a different set of parameters.

According to some embodiments of the present disclosure, the curing andthe ablation is by different systems.

According to some embodiments of the present disclosure, the methodcomprises removing a debris dispensing of the additional buildingmaterial on non-vacant regions. According to some embodiments of thepresent disclosure, the removal is by a laser beam.

According to some embodiments of the present disclosure, the methodcomprises elevating the receiving medium prior to the dispensing of theadditional building material, to ensure removal of the additionalbuilding material during the straightening, substantially from all onnon-vacant regions.

According to some embodiments of the present disclosure, the methodcomprises generating gas flow over the layer following or during theablation, so as to remove building material debris and/or residue.According to some embodiments of the present disclosure, the gascomprises air.

According to some embodiments of the present disclosure, the ablationcomprises laser ablation. According to some embodiments of the presentdisclosure, the laser ablation is a pulsed laser ablation.

According to some embodiments of the present disclosure, the methodcomprises receiving input pertaining to a type of the building material,accessing a computer readable medium storing pulse energy datacorresponding to the type of the building material, and setting pulseenergy for the pulsed laser ablation based on the pulse energy data.

According to some embodiments of the present disclosure, the ablationcomprises Computer Numeric Controlled (CNC) ablation.

According to some embodiments of the present disclosure, the methodcomprises at least partially removing solvent from the buildingmaterial, prior to the straightening.

According to some embodiments of the present disclosure, the methodcomprises ablating a cavity in at least one of the layers, and placing aforeign element in the cavity.

According to some embodiments of the present disclosure, the placing isby a robotic arm.

According to some embodiments of the present disclosure, the methodcomprises the foreign element is an electronic device, and the methodcomprises forming a conductive track in electrical contact with theelectronic device.

Selected operation of the method as delineated above can be executedaccording to some embodiments of the present disclosure, by an SFFsystem. Hence, according to an aspect of some embodiments of the presentdisclosure, there is provided a system for solid free form fabrication(SFF). The system comprises: an input for receiving SFF data, whereinthe SFF data collectively pertains to a three-dimensional shape of anobject and comprises a plurality of slice data each defining a layer ofthe object. The system also comprises a dispensing head configured fordispensing a building material, a leveling device for straightening thebuilding material, an ablation system for ablating the buildingmaterial, and a controller. In various exemplary embodiments of thepresent disclosure, the controller has a circuit configured forcontrolling the ablation system to perform selective ablation, for eachof at least a few of the layers, according to slice data correspondingto the layer.

According to some embodiments of the present disclosure, the systemcomprises at least one additional dispensing head configured fordispensing at least one additional building material onto the buildingmaterial, to fill vacant regions formed in the layer by the selectiveablation. The resolution of the dispensing of the additional buildingmaterial is optionally and preferably less than a resolution of theselective ablation.

According to some embodiments of the present disclosure, the controlleris configured to operate the ablation system also for at least partiallycuring the building material and/or the additional building material.

According to some embodiments of the present disclosure, the systemcomprises a building material curing system.

According to some embodiments of the present disclosure, the controlleris configured for operating the ablation system to remove a debrisdispensing of the additional building material on non-vacant regions.

According to some embodiments of the present disclosure, the controlleris configured for elevating a receiving medium receiving the buildingmaterial prior to the dispensing of the additional building material.

According to some embodiments of the present disclosure, the systemcomprises a gas flow generator configured for generating gas flow overthe layer following or during the ablation, so as to remove buildingmaterial debris and/or residue.

According to some embodiments of the present disclosure, the theablation system comprises a laser ablation system. According to someembodiments of the present disclosure, the laser ablation system isconfigured to provide laser pulses.

According to some embodiments of the present disclosure, the controlleris configured to receiving input pertaining to a type of the buildingmaterial, to access a computer readable medium storing pulse energy datacorresponding to the type of the building material, and to control thelaser ablation system to adjust a pulse energy of the ablation based onthe pulse energy data.

According to some embodiments of the present disclosure, the ablationsystem comprises a Computer Numeric Controlled (CNC) system.

According to some embodiments of the present disclosure, the systemcomprises a drying system for at least partially removing solvent fromthe building material, prior to the straightening.

According to some embodiments of the present disclosure, the controlleris configured for ablating a cavity in at least one of the layers, toallow placing a foreign element in the cavity. According to someembodiments of the present disclosure, the system comprises a roboticarm configured for placing the foreign element in the cavity.

According to some embodiments of the present disclosure, the foreignelement is an electronic device, and the controller is configured forforming a conductive track in electrical contact with the electronicdevice.

According to some embodiments of the present disclosure, the electronicdevice is selected from the group consisting of a radiation transmitter,a radiation receiver, a radiation transceiver, a transistor, a diode, anelectronic circuit, a camera and a processor.

Unless otherwise defined, all technical and/or scientific terms usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which the present disclosure, pertains. Althoughmethods and materials similar or equivalent to those described hereincan be used in the practice or testing of embodiments of the presentdisclosure, exemplary methods and/or materials are described below. Incase of conflict, the patent specification, including definitions, willcontrol. In addition, the materials, methods, and examples areillustrative only and are not intended to be necessarily limiting.

Implementation of the method and/or system of embodiments of the presentdisclosure can involve performing or completing selected tasks manually,automatically, or a combination thereof. Moreover, according to actualinstrumentation and equipment of embodiments of the method and/or systemof the present disclosure, several selected tasks could be implementedby hardware, by software or by firmware or by a combination thereofusing an operating system.

For example, hardware for performing selected tasks according toembodiments of the present disclosure could be implemented as a chip ora circuit. As software, selected tasks according to embodiments of thepresent disclosure could be implemented as a plurality of softwareinstructions being executed by a computer using any suitable operatingsystem. In an exemplary embodiment of the present disclosure, one ormore tasks according to exemplary embodiments of method and/or system asdescribed herein are performed by a data processor, such as a computingplatform for executing a plurality of instructions. Optionally, the dataprocessor includes a volatile memory for storing instructions and/ordata and/or a non-volatile storage, for example, a magnetic hard-diskand/or removable media, for storing instructions and/or data.Optionally, a network connection is provided as well. A display and/or auser input device such as a keyboard or mouse are optionally provided aswell.

In accordance with another feature of the present disclosure, a methodfor solid free form fabrication (SFF) may include dispensing a supportmaterial having an intrinsic “support material energy damage level” atwhich exposure/subjection to a first amount of energy, exceeding thesupport material energy damage level, alters the support material.Additionally, the support material may have an “intrinsic supportmaterial energy ablation threshold” at which a second amount of energy,which is higher than the first amount of energy and exceeds the “supportmaterial energy ablation threshold,” ablates the support material. Themethod further includes dispensing an active material having an“intrinsic active material energy damage level” at which exposure to athird amount of energy, exceeding the “active material energy damagelevel,” alters the active material.

Further, the active material may have “an intrinsic active materialenergy ablation threshold” at which a fourth amount of energy, which ishigher than the third amount of energy and exceeds the “active materialenergy ablation threshold,” ablates the active material. Further, the“active material energy damage level” may be higher than the “supportmaterial energy ablation threshold.” Further, in accordance with themethod, the active material and the support material may deposited so asto form a combined material and exposing the combined material to aprocessing amount of energy such the combined material is modified.

In another feature, the processing amount of energy that the combinedmaterial is exposed to may be at least equal to the first amount ofenergy and less than the second amount of energy so as to alter thesupport material without ablation.

In yet another feature, the processing amount of energy that thecombined material may be exposed to may be at least equal to the secondamount of energy and less than the third amount of energy so as toablate the support material without altering the active material.

Further, the processing amount of energy that the combined material maybe exposed to may be at least equal to the third amount of energy andless than the fourth amount of energy so as to alter the active materialwithout ablation.

Furthermore, the processing amount of energy that the combined materialmay be exposed to is at least equal to the fourth amount of energy so asto ablate the active material.

Additionally, the active material may include a plurality of differentactive materials, and the “active material energy damage level” of eachof the different active materials may be higher than “the supportmaterial energy ablation threshold.”

Another feature may include emitting a laser beam at differingintensities to expose the combined material to varying amounts ofenergy. For example, a feature of the present disclosure may includeemitting the laser beam at an intensity corresponding to the secondamount of energy. In addition, a feature of the present disclosure mayinclude depositing the active material and the support material inlayers according to slice data corresponding to formation of each of thelayers.

Further, a feature of the present disclosure may include depositing anuppermost support material layer (e.g., deposited as part of thecombined material) that is entirely made of the material of the supportmaterial. Further, by emitting the laser beam from the laser source toexpose selected regions of the uppermost support material layer to thesecond amount of energy, selective ablation of the uppermost supportmaterial layer may be accomplished. As a result, the uppermost supportmaterial layer may have vacant regions formed therein; thereby,uncovering regions of the active material that were once covered by theselectively ablated regions of the uppermost support material layer.

Additionally, a feature of the present disclosure may include depositingan uppermost active material layer on top of un-ablated portions of theuppermost support material layer and within the vacant regions. Theuppermost active material layer may be entirely made of the activematerial and leveled. Further, still another feature an outer surface ofthe uppermost active material layer may be ablated to remove residue.Further, another feature may include ablating the leveled uppermostactive material layer to provide a texturized surface, for example, inorder to improve adhesion of a subsequent layer to-be-deposited on thetexturized surface.

Another feature of the present disclosure, for example, of athree-dimensionally shaped object, may include providing a printerpressing assembly for forming material layer(s.) The printer pressingassembly may include a support assembly having a support surface, adriver and a press stop. The driver may change an elevation of thesupport surface relative to an elevation of the press stop. Further, theprinter press assembly may include a nozzle configured to dispense amaterial onto a support surface. Further, the press may be configured tobe positioned opposite to the support surface and move relative to thesupport. In addition, the press stop may be configured to be elevatedabove the support surface to engage an abutment surface of the press,thereby setting a pre-determined distance between the contact surface ofthe press and the support surface. Further, the press stop may include awall surrounding the support surface. As an alternative, the press stopmay include a plurality of elongated stops.

Further, the press may have a plate-shaped surface (e.g., planarsurface) provided with the contact surface and configured to bepositioned opposite to the support surface.

In another feature of the present disclosure, the press may include aroller configured to level a material deposited on the support surfaceby translating in a direction parallel to the support surface. Theroller may include a stationing rod and a movable rod, wherein thestationary rod engages at least a portion of the press stop and themovable rod translates in the direction parallel to the support surfaceto level the material deposited on the support surface.

In yet another feature, a foil may extend around outer peripheries ofthe stationing rod and the movable rod to come into direct engagementwith the material deposited on the support surface as the movable rodtranslates in the direction parallel to the support surface. Further,the foil extending around the outer periphery of the movable rod may beoriented at an acute angle with respect to the support surface as thefoil departs/separates from contact with the outer periphery of themovable rod.

Additionally, a first end of the foil may be wound around a firstroll/spool and a second end of the foil may be connected to a secondroll/spool such that the foil is released from at least one of the firstand second spools as the movable rod translates. In another feature, acuring member may cure, dry or otherwise harden the material depositedon the support surface.

In another feature, the printing assembly may be provided with a lasersource configured to emit a laser beam to ablate the material depositedon the support surface. Further, the press stop may be provided as awall that includes first and second walls (of which at least one may bemotorized).

Additionally, in accordance with a feature of the present disclosure,the first wall may be configured to be elevated to a different heightrelative to the second wall to provide an inclined engagement surfacethat engages the abutment surface of the press. Further, at least one ofthe first wall and second wall may be configured to be moved towards thepress (e.g., the walls may be coupled to a motor configured to elevatethe walls in, e.g., a vertical direction).

In accordance with another feature, a method of solid free formfabrication may include providing a press and a support assembly havinga support surface, a driver and a press stop. Further, the driver may beconfigured to elevate and lower the support surface relative to thepress stop. In addition, the method may include positioning the supportsurface such that a predetermined distance is defined between a surfaceof the press stop, which is configured to engage an abutment surface ofthe press, and a support surface.

Further, the method may include depositing a first material onto thesupport surface, bringing the surface of the press stop and the abutmentsurface of the press into contact with each other such that the firstmaterial is pressed into a first material layer having a thicknesscorresponding to the predetermined thickness, separating the press stopand the abutment surface of the press from each other, and selectivelyablating the first material layer to form vacant regions within thefirst material layer.

A further feature may include dispensing at least a second material ontothe first material layer to fill the vacant regions formed within thefirst material layer, and bringing the surface of the press stop and theabutment surface of the press into contact with each other such that thesecond material is leveled. Also, when a thin residue layer of thesecond material remains after the second material is leveled, theresidue layer may be ablated to remove at least a portion of the residuelayer.

Further, the entire residue layer may be removed by ablation. In anotherfeature of the present disclose, at least regions of the residue layerimmediately surrounding the second material that fills the vacantregions of the first material are removed. Also, the method may includeat least one of an upper surface of the first material layer and aleveled surface of the second material (e.g., residue on an outer layerof the combined material) being ablated to provide a texturized surfaceto improve adhesion of a subsequent layer deposited on the texturizedsurface. Also, as a further feature, the first material may be at leastpartially cured. Further, in accordance with another feature, at leastone of the first material and the second material may be partiallycured. The first and second material may be partially cured before orafter pressing the material(s).

In yet another feature, a method of solid free form fabrication usingthe printer pressing assembly of the present disclosure may includeproviding the press strop with a first press stop and a second pressstop. Further, the method may include elevating the first press stop toa different height relative to the second press stop so as to provide aninclined engagement surface that engages the abutment surface of thepress such that the press is oriented at angle with respect to thesupport surface. Further, the method may include progressively loweringan elevation of one of the first press stop and the second press stopsuch that the first material is progressively pressed by the press in adirection from one end of the support surface towards another end of thesupport surface at which the one of the first press stop and secondpress stop is lowered. Thereby, eliminating air bubbles within the firstmaterial as the contact surface of the press becomes oriented horizontalto the support surface.

Further, in accordance with another feature, a solid free formfabrication system incorporating the printer pressing assembly of thepresent disclosure may include an ablation system configured to cure andablate the material dispensed onto the support surface, wherein thecuring and ablating is performed by the same ablation system, which isconfigured to operate at a different set of parameters. Further, theablation system may include a pulse laser configured to emit a laserbeam at different intensities.

Further, in accordance with yet another feature of the presentdisclosure, a solid free form fabrication system incorporating theprinter pressing assembly may further include a curing member configuredto cure the material dispensed onto the support surface and an ablationsystem configured to ablate the material dispensed onto the supportsurface. Further, the ablation system may include a Computer NumericControlled (CNC) system.

In another feature of the present disclosure, a system for solid freeform fabrication may include a material deposited on a surface, and alaser source configured to emit a laser beam at different setparameters. Further, the laser source, when emitting the laser beam at afirst setting of the different set parameters, may be configured to curethe material deposited on the surface. The laser source, when emittingthe laser beam at a second setting of the different set parameters, maybe configured to sinter the material deposited on the surface. The lasersource, when emitting the laser beam at a third setting of the differentset parameters, may be configured to ablate the material deposited onthe surface. Further, the laser source may include an ultraviolet fiberlaser. Further, a pulse duration of the laser may be adjusted in settingone of the first setting, the second setting and the third setting.Additionally, the pulse duration may be configured to be selected withina range of between 2-200 nanoseconds to perform a selected one ofcuring, sintering and ablating.

It should be appreciated that the controller, data processor, firmware,software, hardware, manually, and automated controlled operations asdescribed above are equally applicable to all disclosedembodiments/features unless otherwise noted.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

Some embodiments of the present disclosure are herein described, by wayof example only, with reference to the accompanying drawings. It isstressed, however, that the particulars shown are by way of example andfor purposes of illustrative discussion of embodiments of the presentdisclosure. In this regard, the description taken with the drawingsmakes apparent to those skilled in the art how embodiments of thepresent disclosure may be practiced.

In the drawings:

FIG. 1 is a flowchart diagram of a method suitable for SFF, according tovarious exemplary embodiments of the present disclosure;

FIGS. 2A-M are process illustrations of the method of FIG. 1, accordingto various exemplary embodiments of the present disclosure;

FIG. 3 is a flowchart diagram of a method suitable for SFF of afunctional object, according to some embodiments of the presentdisclosure;

FIGS. 4A-I are process illustrations of the method of FIG. 3, accordingto various exemplary embodiments of the present disclosure;

FIGS. 5A-D are schematic illustration of an SFF system according to someembodiments of the present disclosure; and

FIG. 6 is a flow chart diagram describing a representative example of anSFF process, according to some embodiments of the present disclosure;

FIG. 7 is a flow chart diagram describing a representative example of aprocess for combining a foreign element with a solid freeform fabricatedobject, according to some embodiments of the present disclosure;

FIG. 8A-H illustrates a process in which a support material and activematerial may be deposited with selective ablation, cleaning andtexturization;

FIG. 9 is a flow chart diagram describing a representative process fordepositing/dispending first and second materials;

FIG.10 is a flow chart diagram describing an exemplary process forsetting a predetermined thickness for a material that may besubsequently cured and leveled;

FIGS. 11A-G illustrates a pressing apparatus and various method featuresfor forming material layer(s) of, for example, a three dimensionallyshaped object;

FIG. 12A-C illustrates a method for removing (or partially cleaning)residue from, for example, an outer surface of a material by using lowenergy ablation;

FIGS. 13A-G illustrates a pressing apparatus in the form of a rollingdevice and various method features for forming material layers of, forexample, a three dimensionally shaped object;

FIGS. 14A-E illustrates a pressing apparatus having first and secondpress stops that may be set a different elevations and various methodfeatures for forming material layers of, for example, a threedimensionally shaped object;

FIGS. 15A-E illustrates a recycling device for recycling excessmaterial;

FIG. 16 illustrates different operation modes of the same laser capableof performing curing, sintering and ablation; and

FIG. 17 is a graph illustrating material damage and ablation as afunction of energy.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present disclosure relates to, among other things, SFF and, moreparticularly, but not exclusively, to a method and system for SFF by anadditive-ablative process.

Before explaining non-limiting embodiments of the present disclosure indetail, it is to be understood that the present disclosure is notnecessarily limited in its application to the details of constructionand the arrangement of the components and/or methods set forth in thefollowing description and/or illustrated in the drawings and/or theExamples. The present disclosure is capable of other embodiments or ofbeing practiced or carried out in various ways.

Referring now to the drawings, FIG. 1 is a flowchart diagram and FIGS.2A-M are process illustrations of a method suitable for SFF, accordingto various exemplary embodiments of the present disclosure. It is to beunderstood that, unless otherwise defined, the operations describedhereinbelow can be executed either contemporaneously or sequentially inmany combinations or orders of execution. Specifically, the ordering ofthe flowchart diagrams is not to be considered as limiting. For example,two or more operations, appearing in the following description or in theflowchart diagrams in a particular order, can be executed in a differentorder (e.g., a reverse order) or substantially contemporaneously.Additionally, several operations described below are optional and maynot be executed.

As illustrated in FIG. 1, a method of SFF may begin with 10 and continueto 11 (i.e., at which SFF data that collectively pertains to athree-dimensional shape of the object may be received.) For example, thedata may be received by a data processor 34 operatively associated withan SFF system 30 (see FIGS. 2A-M) that executes the method or by acontroller 32 of the SFF system 30. For example, the data processor 34may access a computer-readable storage medium (not shown) and retrievethe data from the medium. The data processor 34 can also generate thedata, or a portion thereof, instead of, or in addition to, retrievingdata from the storage medium, for example, by utilizing a computer aideddesign (CAD) or computer aided manufacturing (CAM) software. Forexample, the SFF data may include a plurality of slice data each ofwhich may define a layer of the object to-be-manufactured. The dataprocessor 34 may transfer the data, or a portion thereof, to thecontroller 32 of the SFF system 30. Further, the controller 32 mayreceive the data on a slice-by-slice basis. The operation of the dataprocessor and controller are applicable to all disclosed embodimentsunless otherwise stated.

The data can be in any data format known in the art, including, withoutlimitation, stereolithography (STL) format, additive manufacturingformat (AMF), surface precursor data (SPD) format and the like.

The following operations are described with reference to particularlayers of the object, and can be repeated for each of at least a few ofthe layers.

The method proceeds to 12 at which a building material 36 is dispensedon a receiving medium (FIG. 2A). The receiving medium can be a workingsurface 38 of the system 30, as illustrated in FIG. 2A, or a previouslyformed layer 40-1, 40-2, etc . . . as illustrated, for example, in FIG.2L. The building material 36 can be dispensed by a dispensing head 42 ofsystem 30. The dispensing head 42 can scan the working surface 38 ofsystem 30 along a scanning direction x (see Cartesian coordinate systemin FIG. 2A) and dispense the material while scanning.

Any type of dispensing head suitable for SFF can be employed, including,without limitation, an inkjet head, an extruder head, a single nozzlehead, and the like. The advantage of the additive-ablative process ofpreferred embodiments of the present disclosure is that even though thefinal object can have high in-layer resolution, the dispensing need notnecessarily be at high resolution. Thus, for example, the dispensinghead can operate at an in-layer resolution that is characterized by avoxel size of 1 cubic millimeter or more.

The method optionally and preferably proceeds to 13 at which solvent maybe at least partially removed from the building material. This can bedone, for example, by a drying system 56 that heats the dispensedmaterial. The heating can be applied directly to the dispensed material,for example, by radiation (FIG. 2C), or it can be applied within achamber 58 at which the dispensing is executed.

The method can then continue to 14 at which the dispensed buildingmaterial is leveled/straightened/planarized (FIG. 2B). Preferably, onlythe most newly dispensed building material is leveled, but the presentembodiments also contemplate leveling also previously dispensed buildingmaterial (for example, building material beneath the newly dispensedbuilding material). The leveling can be by a leveling device 44, suchas, but not limited to, a blade, a squeegee, a roller or the like.Further, the leveling device may be provided as an “air knife” that, forexample, allows controlling the resolution/thickness of the buildingmaterial 36 by adjusting the gas pressure at an output of air knife.Another advantage is that it eliminates the need to clean or replace ablade, a squeegee, a roller or the like.

Furthermore, regardless of the type of leveling device, buildingmaterial removed by the leveling device 44 may be recycled (if desired.)For example, in order to recycle material that has been leveled (e.g.,with a blade 44) a separate reservoir may be provided for each material.As illustrated in FIG. 15A, an excess first material may be directedinto a first recycling reservoir as the excess first material isdisplaced during leveling. Similarly, an excess second material may bedirected into a second recycling reservoir as the excess second materialis displaced during leveling. See FIGS. 15D and 15E. Of course, as manyrecycling reservoirs as needed may be provided to separately containdifferent materials. Furthermore, the recycling reservoirs may becoupled together via a rotating mechanism (e.g., a rotary motor)configured to selectively position a corresponding one of the recyclingreservoirs so as to separately receive the corresponding excess materialthat is removed during leveling. See FIGS. 15A-15E. It should beappreciated that leveling is not limited to providing a planar surface,but rather should be understood to encompass flattening, smoothing orshaping a surface to a desired form or profile.

The method may continue to 15 at which the building material may beselectively ablated (FIG. 2D). The ablation may be accomplished by anysuitable ablation system 46. FIG. 2D illustrates an embodiment in whichsystem 46 comprises a laser scanning system that horizontally scans alaser beam 47 over the building material. For example, a pulsed laserbeam may perform the laser ablation. In some embodiments, the dataprocessor may optionally, and preferably, receive input pertaining to atype of the building material, accesses a computer readable mediumstoring pulse energy data corresponding to the type of buildingmaterial, and signals the controller to set the pulse energy for thepulsed laser ablation based on the pulse energy data. Also contemplatedare embodiments in which system 46 is a Computer Numeric Controlled(CNC), or any other system, which may selectively ablate the buildingmaterial. In the present disclose, reference to “ablation” or “ablationsystem” in the context of a Computer Numerical Controlled (CNC) systemor any other system may refer to removal of material by cutting orotherwise machining.

The ablation may be excited or otherwise operated to form atwo-dimensional ablation pattern according to the slice data of therespective layer. Thus, pre-determined or specified horizontal locationsin the layer (which according to the slice data is to be unoccupied bythe building material) may be ablated at an appropriate stage after thebuilding material is dispensed. As illustrate in FIG. 2D, the ablationresults in a layer having vacant regions 48 that are devoid of buildingmaterial.

In some embodiments of the present disclosure, the method proceeds to 16at which a debris deposition of building material on non-vacant regionsmay be removed. The debris deposition is typically formed by theablation 15, and/or due to imperfectness of the straightening (orleveling) 14. The debris deposition can be removed, for example, by alaser beam. For example, when ablation system 46 comprises a laserscanning system, the laser scanning system can be used also for theremoval of the debris deposition. Typically, the laser is applied at adifferent set of parameters for the removal of the debris depositionthan for the ablation. The debris deposition can alternatively oradditionally also be removed by gas flow (e.g., airflow), for example,by means of a gas flow generator 54, as will now be explained withreference to FIG. 2E and FIG. 2F, which are magnified views of thedispensed building material 36. The ablation system may generate (bymeans of laser beam 47, in the present example) a budge 82 at the pointof contact with the building material 36, due to a heat zone generatedand/or applied at the contact (FIG. 2E). In addition, debris deposition84 may also be generated away from the heat zone. Gas flow generator 54generates a gas flow that removes, at least partially, the debrisdeposition 84. The budge 82 may be removed by the straightening of thenext layer.

The method optionally and preferably continues to 17 at which anadditional building material 50 is dispensed onto building material 36to fill vacant regions 48 (FIGS. 2G and 2H). The in-layer resolution ofthe dispensing 17 is optionally and preferably less than the resolutionof the selective ablation 15. In other words, the material 50 isdispensed to form a continues region of material 50 that encompasses atleast one of vacant regions 48 by its entirety, and that is laterallylarger than that vacant region(s). This ensures that material 50 fillsthe vacant region(s) created by the ablation. In some embodiments of thepresent disclosure, the dispensing of building materials 36 and 50provide the same lateral coverage (e.g., both materials are dispensedover the entire layer, irrespectively of lateral slice data), and insome embodiments of the present disclosure, the dispensing of material36 and/or material 50 is/are selective.

For example, the building material 36 may be deposited as viscousmaterial dropped from a dispensing head of nozzle or by continuousdispensing. For example, the deposit resolution may be more than 200 μm.Further, the “ablated” resolution may be on the order of a laser spotsize which may be tuned from about 5 to 40 μm. Also, in certainapplications, the ablated resolution may be below 2 μm.

While the embodiments below are described with a particular emphasis totwo materials 36 and 50, it is to be understood that the method can beexecuted also with one building material or more than two buildingmaterials.

Each of the materials 36 and 50 can serve as a modeling material fromwhich the final object, once fabricated, is made, or as a sacrificialsupport material that supports parts of the object during fabricationbut is subsequently removed and does not form parts of the final object.Typically, one of the dispensed materials is a support material and allother materials are modeling materials, but this need not necessarily bethe case, since, for some applications, it may be desired to have morethan one type of support material or to fabricate an object without asupport material.

The dispensing 17 can be by the same dispensing head 42, except withdifferent material, or, more preferably by a different dispensing headcontaining material 50. The dispensing heads that dispense the differentmaterials can be of the same or different types, as desired. Arepresentative example of a dispensing system having a plurality ofdispensing heads is described below.

In some embodiments of the present disclosure, the method continues to18 at which the additional building material 50 is leveled (orstraightened) (FIG. 2I), as further detailed hereinabove. Preferably,the working surface 38 is elevated prior to the dispensing 17 or priorto the leveling (or straightening)18, to ensure removal of material 50during leveling (or straightening) 18, substantially from all onnon-vacant regions. This embodiment is illustrated in FIG. 2J which is amagnified view of section A in FIG. 2I. As illustrated in FIG. 2J, theremay be a residue of material 50 over a non-vacant region 37 of material36. Elevation of the working surface 38 at amount of δz prior to thedispensing 17 or leveling (or straightening) 18, ensures removal of thisresidue, or at least reduces the amount of the residue. The extent δz ofthe elevation is preferably less than the thickness Δz of a single layer(e.g., 0.1 Δz). Optionally and preferably, the method executes 16following the leveling (or straightening) 18, to remove debrisdispensing of material 50 on non-vacant regions occupied by material 36.

Material 36 and/or 50 is optionally and preferably a curable material.In these embodiments, the method proceeds to 19 at which material 36and/or 50 is/are cured, at least partially. The curing can be by heator, more preferably, by radiation, and may be executed by a curingsystem 52 (see FIG. 2I) that is optionally and preferably included insystem 30. In a preferred embodiment, the curing may be by laserradiation. These embodiments are particularly useful when ablationsystem 46 comprises a laser scanning system, in which case the samelaser scanning system can be used both for the ablation 15 and for thecuring 19, wherein a different set of operation parameters is used forthe ablation and for the curing. The set of operation parameters caninclude any of laser power, laser focal spot size and laser wavelength,as well as radiation protocol, e.g., continuous wave (CW) or pulsedradiation, wherein when the radiation protocol is pulsed radiation, theset of parameters may include at least one of pulse duration, and pulserepetition rate. Alternatively, the ablation and curing can be executedby different systems, in which case system 30 may comprise both ablationsystem 46 and curing system 52.

Material 36 and/or 50 can alternatively be in, for example, a powderform, a metal colloid, a ceramic colloid, a semiconductor particle inkcolloid, a paste, etc., in which case sintering and de-binding (e.g.,laser sintering) may be applied instead of curing.

Once a layer is completed (see, e.g., FIG. 2K, layer 40-1), the verticaldistance between the working surface 38 and the dispensing head 42 mayoptionally and preferably be increased (e.g., by lowering the workingsurface 38, see FIG. 2K) by an amount that is equal or approximatelyequal to the thickness of the layer, and the method may loop back to 11or 12 to begin the formation of the subsequent layer (see FIG. 2L, layer40-2, and FIG. 2M, layer 40-3).

The method ends at 20.

FIG. 3 is a flowchart diagram and FIGS. 4A-I are process illustrationsof a method suitable for SFF of a functional object, according tovarious exemplary embodiments of the present disclosure. At least someof the operations described below can be executed by system 30.

The method begins at 60 and continues to 61 at which one or more layers40-1, . . . , 40-N of building materials are formed (FIG. 4A). This isoptionally and preferably achieved by executing one or more of theoperations of method 10 described above with respect to FIGS. 1 and2A-I. The method continues to 62 at which a cavity 72 is ablated in atleast one of the layers (FIG. 4B). The cavity is preferably ablated inregions in the layer(s) that contain a modeling material and not inregions of the layer(s) that contain support material. The ablation 62can be done using ablation system 46 of system 30. The method continuesto 63 at which a foreign element 74 is placed in cavity 72. The size andshape of cavity 72 is preferably selected to be compatible with the sizeand shape of foreign element 74 so as to allow foreign element 74 to fitinto cavity 72, as illustrated in FIG. 4C, and FIG. 4D which is amagnified view of cavity 72 and foreign element 74. The placement isoptionally and preferably by a robotic arm (not shown, see FIG. 5D),which can be also part of system 30.

The foreign element 74 can be of any type. Preferably, the foreignelement is not fabricated by system 30. Optionally, the foreign elementis fabricated by a method other than SFF. Representative examples oftypes of foreign elements suitable for the present embodimentsincluding, without limitation, electronic components (e.g., a diode, atransistor, an inductor, a capacitor), electronic devices (e.g., a lightsource, a camera, a sensor, a radiation transmitter, a radiationreceiver, a radiation transceiver, an electronic circuit, a processor),mechanical devices (e.g., a wheel, a transmission gear, a MEMS), atransmission line (e.g., an electrically conductive track, a heatconduction element, a waveguide), and the like.

It is to be understood that while FIGS. 4C-I illustrate a single foreignelement placed in a single cavity, this need not necessarily be thecase, since, for some applications, it may be desired to form aplurality of cavities and placing a respective plurality of foreignelements in the cavities. Also contemplated, are embodiments in whichmore than one foreign element is placed in the same cavity. When aplurality of foreign elements are placed, either in separate cavities orin the same cavity, they can be of the same type (e.g., replicas of eachother) or of different types.

Once the foreign element is placed in the cavity, the method optionallyand preferably proceeds to 64 at which one or more additional layers ofbuilding material are formed, for example, by dispensing buildingmaterial, leveling (or straightening) the dispensed building materialand optionally and preferably selectively ablating the dispensedbuilding material, as further detailed hereinabove. In some embodimentsof the present disclosure, the method forms or places 65 a conductivetrack 76 in electrical contact with element 74. This is particularlyuseful when element 74 is an electronic device or electronic component.

A preferred procedure for forming conductive track 76 according to someembodiments of the present disclosure is illustrated in FIGS. 4F-4H. Abuilding material (which can be the same as material 36 or of adifferent type) is dispensed over element 74 and is then leveled (orstraightened) and ablated as further detailed hereinabove to form vacantregions at one or more sides of element 74 (FIG. 4F). A conductivebuilding material is then dispensed as an additional building materialthat fills the vacant regions 48, as further detailed hereinabove. Theconductive building material is then leveled (or straightened) asfurther detailed hereinabove, thereby forming conductive track 76 withinvacant regions 48 (FIG. 4G). Additional layers 78 can be formed 66 ontop of track 76 (FIG. 4H). Once the support material 50 is removed (FIG.4I) a functional object 80 is formed. When a conductive track 76 isformed, the removal of support material preferably exposes the ends ofthe conductive track, to allow their connection to external device. Inthe example of FIG. 4I, element 74 is a radiation source (e.g., a lightemitting diode), which is powered by a voltage source 82 connected tothe ends of via conductive track 76 to emit radiation 84.

The method ends at 67.

FIGS. 5A-D are schematic illustration of an SFF system 30 according tosome embodiments of the present disclosure. System 30 comprises aworking surface 38 and a dispensing system 92 for dispensing a buildingmaterial on the working surface. System 30 can additionally comprise avertical drive 94 configured to vary a vertical distance (along thevertical direction z, see Cartesian coordinate system in FIG. 5A)between working surface 38 and system 92. In the representative exampleillustrated in FIG. 5A, which is not to be considered as limiting, drive94 establishes a vertical motion of working surface 38, by means of aZ-stage 96.

System 92 can comprise one or more dispensing heads, such as, but notlimited to, head 42 described above. FIG. 5B illustrates arepresentative example of system 92. In the illustrated embodiments,system 92 comprises four dispensing heads 42-1, 42-2, 42-3 and 42-4, butthis need not necessarily be the case since any number of dispensingheads can be employed. Each of the dispensing heads of system 92 candispense a different building material. Alternatively, two or more ofthe dispensing heads, can dispense the same material, for example, toincrease the throughput. Preferably, at least one of the dispensingheads dispenses a modeling material and at least one of the dispensingheads dispenses a support material.

System 30 optionally and preferably comprises a leveling device 44 forleveling (or straightening) the dispensed building material, as furtherdetailed hereinabove. Leveling device 44 can be, for example, a blade, asqueegee, a roller or the like. The vertical distance between theleveling device 44 and the working surface 38 is preferably selected inaccordance with the desired thickness of the layer. For example, when itis desired to fabricate a plurality of layers, each of height h, then,for the nth layer, the vertical distance between the leveling device 44(or the press 144 or 244, to be discussed later) and the working surface38 can be set to nh.

System 30 preferably also comprises an ablation system 46 thatselectively ablates the dispensed material as further detailedhereinabove. Ablation system 46 can be of any type, including, withoutlimitation, a laser scanning system, a CNC or the like. FIG. 5Cillustrates a representative example of system 46, in the embodiment inwhich system 46 comprises a laser scanning system. In these embodiments,system 46 can comprise a laser beam generator 98 [any suitable laser maybe used, e.g., “a diode pumped solid state laser” (DPSS), a fiber laser,etc.]

that generates laser beam 47, an X-Y scanner 100 that scans beam 47along the horizontal directions x and y (both perpendicular to the zdirection shown in FIG. 5A), and optics 102 that generates a focal spot104 on the dispensed building material.

System 30 can further comprise a controller 32, and optionally andpreferably also a data processor 34, that control the operation ofsystem 30. Alternatively, controller 34 can have electronic computingcapability in which case it is not necessary for system 30 to include aprocessor separately from the controller. Controller 32 and/or processor34 are optionally and preferably configured for controlling system 30 toexecute any of the operations described above.

In some embodiments of the present disclosure, system 30 comprises abuilding material curing system 106 for curing the building material.Alternatively, the curing can be done by means of ablation system 46except at a different set of operation parameters as further detailedhereinabove. System 30 can further comprises a gas flow generator 54that generates gas flow over the formed layers following or duringablation, to remove building material debris and/or residue, as furtherdetailed hereinabove. Optionally and preferably system 30 comprises adrying system 56 for at least partially removing solvent from buildingmaterial, prior to the leveling (or straightening) by device 44, asfurther detailed hereinabove.

System 30 can further comprise a robotic arm 108 that places a foreignelement in a cavity formed in the dispensed layers. This embodiment isillustrated in FIGS. 5D and 5E. FIG. 5E illustrates cavity 72 formed inbuilding material 36. FIG. 5D illustrates robotic arm 108 that picks aforeign element 74 from an array 110 of foreign elements, for example,by means of temporary vacuum attachment. Arm 108 moves in the verticaland horizontal direction, for example, by means of an X-Y-Z stage 112.Arm 108 lifts the element 74 from array 110 moves to cavity 72 andreleases element 74 in cavity 72. Arm 108 and X-Y-Z stage 112 areoptionally and preferably controlled by controller 32.

Further, when intense laser pulse energy is applied to a material,observation can be made based upon an energy function. For example,first a material may experience damage at energy ED (“the damageenergy”) and second, ablation of the materials occur at energy ETh (“thethreshold energy”).

In the case of printing sensitive material, the threshold energy of thesupport EThs must be below the damage energy of the active materials EDa(i.e., EThs<<EDa). It is noted that the “active material” may refer toany building material, sensitive material, or any other material thatmay be un-ablated while subject other materials (e.g., a supportmaterial) to energy sufficient to cause ablation or could be removablewith CNC or other removable system. See FIG. 17. For example, thesupport material may be a low glass temperature polymer having an addedabsorber like pigment or dye exhibiting an adequate or predeterminedwavelength. See FIG. 17. In certain circumstances there is a desire notto ablate sensitive or active materials such as a bio material, organiclight emitting material, organic semiconductor, etc. In addition, highmelting temperature materials like ceramic material for which theablation requires high laser energy may also be provided as the activematerial. See FIG. 17. In accordance with the above, a method for solidfree form fabrication may include dispensing a support material 150having an intrinsic “support material energy damage level” (ED_(s)) atwhich exposure to a first amount of energy, exceeding the supportmaterial energy damage level (ED_(s)), alters the support material 150.See FIG. 8A. This “altering” may refer to any irreversible change, e.g.,a partial deformation or partial sintering that may take place withinthe support material 150.

Additionally, the support material 150 may have an “intrinsic supportmaterial energy ablation threshold” (EThs) at which a second amount ofenergy, which is higher than the first amount of energy and exceeds the“support material energy ablation threshold” (EThs), ablates the supportmaterial. The method further includes dispensing an active materialhaving an “intrinsic active material energy damage level” (EDa) at whichexposure to a third amount of energy, exceeding the “active materialenergy damage level,” (EDa) alters the active material 136. See FIG. 17.

Further, the active material 136 may have “an intrinsic active materialenergy ablation threshold” (ETha) at which a fourth amount of energy,which is higher than the third amount of energy and exceeds the “activematerial energy ablation threshold” (ETha) ablates the active material136. Further, the “active material energy damage level” (EDa) may behigher than the “support material energy ablation threshold” (EDs).Further, in accordance with the method, the active material 136 and thesupport material 150 may deposited to form a combined material andexposing the combined material to the second amount of energy may ablatethe support material 150 without altering the active material 136. SeeFIG. 17 and FIGS. 8B and 8C. It is noted that the reference/mention of“combined material” in the present disclosure generally refers to, forexample, an overall material that may include any of a number of layersand/or regions that may have portions or segments made of more than onematerial. For example, an individual layer or region may have a firstportion made of one material (e.g., an active material) and a secondportion made of a second material (e.g., a support material).Additionally, to form multiple layers of an overall material individuallayers could be stacked or formed on top of each other; in which case,for example, one of the layers could be defined entirely or partially bya first material region, and another of the layers could be definedentirely or partially by a second material region.

Further, the active material 136 and/or support material 150 may beprovided in any suitable number depending upon the desired application.For example, active material 136 may include a plurality of differentactive materials, and the “active material energy damage level” of eachof the different active materials may be higher than “the supportmaterial energy ablation threshold.” Additionally, if desired, more thanone different support material may also be deposited/dispensed to formthe combine material.

Further, the processing amount of energy that the combined material isexposed to may be at least equal to the first amount of energy and lessthan the second amount of energy so as to alter the support materialwithout ablation. That is, it is possible to subject the supportmaterial to an amount of energy that does not ablate the supportmaterial or alter the active material at all. In yet another feature,the processing amount of energy that the combined material may beexposed to may be at least equal to the second amount of energy and lessthan the third amount of energy so as to ablate the support materialwithout altering the active material.

In addition, the processing amount of energy that the combined materialmay be exposed to may be at least equal to the third amount of energyand less than the fourth amount of energy so as to alter the activematerial without ablation. For example, it may be possible to ablate thesupport material and, at the same time, alter the active materialwithout ablation. That is, it is possible to subject the combinedmaterial to an amount of energy that ablates any desired portion of thecombined material. In other words, since the processing amount of energycan be set to exceed the active material energy ablation threshold, anydesired portion of the combined material may be ablated so as to, e.g.,shape, profile, or penetrate any desired portion of the combinedmaterial.

Additionally, the processing amount of energy that the combined materialmay be exposed to may be at least equal to the fourth amount of energyso as to ablate the active material.

In order to control a depth of the ablation, for example, a duration orintensity of the laser source may be adjusted accordingly. For example,the laser source may be configured to scan a surface of the threedimensionally shaped object or layers thereof at a slower scan rate inorder to ablate the three dimensionally shaped object at a greaterdepth. Similarly, increasing the scan rate may cause the threedimensionally shaped object to be ablated at a much finer (e.g., smalleror high resolution) depth. In addition to adjusting a scan rate of thelaser, an intensity of the laser source may also be adjusted to controlthe depth at which a material is ablated. Further, the intensity of thebeam and the laser scan rate may both be adjusted in order to obtained adesired ablation depth.

Additionally, it should be appreciated that “leveling” as referred to inthe present disclosure may also include flattening, profiling orotherwise shaping a surface of a layer of material(s)to a desiredprofile by using a laser source. Such leveling can also be performed bycontrolling the ablation depth of the laser source.

Another feature may include emitting a laser beam at differingintensities to expose the combined material to varying amounts ofenergy. For example, a feature of the present disclosure may includeemitting the laser beam at an intensity corresponding to the secondamount of energy. (thereby resulting in vacant regions within thesupport material 150, See FIG. 8C.) In addition, a feature of thepresent disclosure may include depositing the active material and thesupport material in layers according to slice data corresponding toformation of each of the layers (i.e., as similarly discussed withrespect to FIGS. 1 and 2 above).

Further, a feature of the present disclosure may include depositing anuppermost support material layer 150 u (e.g., deposited as part of thecombined material) that is entirely made of the material of the supportmaterial 150. Further, by emitting the laser beam from the laser source(e.g., a laser source as described in FIG. 2D) to subject selectedregions of the uppermost support material layer 150 u to the secondamount of energy, selective ablation of the uppermost support materiallayer 150 u may be accomplished (e.g., creating vacant regions asillustrated in FIG. 8C). As a result, the uppermost support materiallayer 150 u may have vacant regions formed therein; thereby, uncoveringregions of the active material 136 that were once covered by theselectively ablated regions of the uppermost support material layer 150u. See FIGS. 8A-8C.

It should be understood that the laser ablation mentioned in relation tothe aforementioned feature can be carried out, where applicable, inaccordance with processes and operations described with respect to FIGS.2A-2M as discussed in detail above.

Additionally, a feature of the present disclosure may include depositingan uppermost active material layer 136 u on top of un-ablated portionsof the uppermost support material layer and within the vacant regions.See FIG. 8D. The uppermost active material layer 136 u may be entirelymade of the material of the active material 136 and leveled. Further,yet another feature may include ablating the leveled uppermost activematerial 136 u layer to remove residue. See FIG. 8E and FIG. 12B.

That is, after leveling or “planarization”of the material layer it maybe necessary to clean residue from the material. In order to clean suchresidue from the material layer a laser ablation with low energy may beapplied to the material layer. See FIGS. 8E and 12A-C.

Such an ablation of residue material may also be beneficial, forexample, in an application where the residue material may beelectrically conductive and otherwise form an unintended or undesirableelectrical pathway between other conductive regions of, for example, acombined material. For example, a laser source may ablate the residuelayer with precision by controlling an ablation depth of the laser asdisclosed in the present disclosure. Therefore, the residue layer may beentirely ablated or only partially ablated at predetermined portions soas to create a discontinuity in the residue layer and prevent, forexample, and electrical pathway between conductive regions that shouldbe electrically isolated from one another.

Further, another feature may include ablating the leveled uppermostactive material layer 136 u to provide a texturized surface, forexample, in order to improve adhesion of a subsequent layerto-be-deposited on the texturized surface. Additionally, random orperiodic texturing of the surface may improve the adhesion of the nextlayer. See FIGS. 8 and 8H.

Therefore, in accordance with a 3D printing process, generally, asupport material may be deposited or dispended (e.g., from a nozzle), apattern may be ablated into the support material, an active material ora subsequent material may be deposited so as to fill the vacant regionsdefined by the ablated material. After leveling (or planarization of)the active material or a subsequent material any remaining residue maybe removed by laser cleaning. For example, by subjecting the residue toa low energy laser beam generated by the laser source and having asufficient energy to ablate the residue layer. See FIG. 9. Further,partial or complete curing of the support material and/or activematerial may take place at any desired stage within the process, i.e.,after the materials are dispensed. See, for example, FIG. 11D.

In addition, a material layer thickness may be defined by setting apredetermined distance between, for example, the support surface thatthe material is deposited on and a surface of the press and/or bysetting a distance between a press stop and the support surface that thematerial is deposited on. After setting the predetermined distance,which corresponds to a predetermined thickness of the material layer,partial curing or drying may take place prior to, or after, leveling orplanarization. See FIG. 10.

Another feature of the present disclosure may include providing aprinter pressing assembly for forming material layers. See FIGS.11A-11D. The printer pressing assembly may include a support surface138, a driver (e.g., a motor capable of elevating and lowering a supportsurface) and a press stop PS.

The driver may change an elevation of the support surface 138 relativeto an elevation of the press stop PS (e.g., similar to the operationdiscussed with respect to FIGS. 2K, 2L and 2M) to define a predetermineddistance or thickness Δz. See FIG. 11B. Further, the printer pressassembly may include a nozzle 142 configured to dispense a material 136onto a the support surface 138. The nozzle may be a single or array ofnozzles providing a “drop on demand” (DOD) printing system for high/lowviscous material. See FIG. 11A. Further, the press 144 may be configuredto be positioned opposite to the support surface 138 and move relativeto the support assembly. In addition, a hydrophobic material or coatinglayer of hydrophobic material may be provided as the contact surface ofthe press 144 in order to prevent sticking between the press 144 andmaterial deposited on the support surface 138. See FIGS. 11B and 11C.Also, the press 144 may be provided on or coupled to an ultra-sonicvibrator (not shown) to avoid sticking during press release. (i.e., fromthe material.)

In addition, the press stop PS may be configured to be elevated abovethe support surface 138 to engage an abutment surface of the press 144,thereby setting the pre-determined distance Δz between contact surfaceof the press 144 and the support surface 138. Further, the press stop PSmay include a wall surrounding the support surface (e.g., an annularwall extending vertically from a base of the support.

As an alternative, the press stop PS may include a plurality ofelongated stops (e.g., rods, shafts, support pins, etc.) arranged, forexample, at intervals, about an outer periphery of the support surface138. It is important to note that the press stop PS is not particularlylimited in that any suitable mechanism form setting a reference distancebetween the support surface 138 and the press 144 may be provided as a“press stop.” Further, the press 144 may have a plate-shaped surface(e.g., planar surface) provided with the contact surface and configuredto be positioned opposite to the support surface 138. See FIG. 11C.

In another feature of the present disclosure, the press may include aroller assembly 244 configured to level a material 136 deposited on thesupport surface 138 by translating in a direction parallel to thesupport surface 138. See FIGS. 13A-13E. The roller assembly 144 mayinclude a stationing rod Rs and a movable rod R_(M), wherein thestationary rod Rs engages at least a portion of the press stop PS andthe movable rod R_(M) translates in the direction parallel to thesupport surface 138 to level the material deposited on the supportsurface. See FIGS. 13A-13E.

In yet another feature, a foil may extend around outer peripheries ofthe stationing rod Rs and the movable rod R_(M) to come into directengagement with the material 136 deposited on the support surface 138 asthe movable rod R_(M) translates in the direction parallel to thesupport surface 138. See FIG. 13A-13E. Further, the foil extendingaround the outer periphery of the movable rod R_(M) may be oriented atan acute angle with respect to the support surface 138 as it separatesfrom contact with the outer periphery of the movable rod R_(M). As aresult, an abrupt angle is defined between the foil wrapping around themovable rod R_(M) and the surface of the material 136 deposited on thesurface to avoid sticking. See FIG. 13GH.

Additionally, a first end of the foil may be wound around a first roll(or spool) and a second end of the foil may be connected to a secondroll (or spool) such that the foil is released from one of the first andsecond rolls as the movable rod R_(M) translates. See FIG. 13A-13E and13G. The press may use a plastic foil which can be replaced during theprinting procedure. Further, the stationary rod R_(s) and movable rodR_(M) may serve to direct the foil and be connected or coupled togetherin the z direction (e.g., vertical or direction of elevation). Thedistance between stationary rod Rs and movable rod R_(M) varies as themovable Rod R_(M) translates in a direction parallel to a supportsurface. Further, at least one roll (or spool) may be motorized toensure proper foil tension so that the foil is as flat as possible. Inaddition, the foil may be provided as a hydrophobic paraffin.

In another feature, a curing member may dry, cure or otherwise hardenthe material deposited on the support surface 138. FIG. 13F. Further,the curing may take place whether the foil is in place or not.

In another feature, the printing assembly may be provided with a lasersource 146 configured to emit a laser beam to ablate the material 136deposited on the support surface. See FIG. 11E. Further, the press stopPS may be provided as a wall that includes first W₁ and second W₂ walls.Additionally, in accordance with a feature of the present disclosure,the first wall W₁ (e.g., a motorized wall connected to a motor andconfigured to elevate the wall vertically above the support surface) maybe configured to be elevated to a different height relative to thesecond wall W₂ to provide an inclined engagement surface that engagesthe abutment surface of the press 144. See FIGS. 14A-14C. It should beappreciated that the walls may be motorized by, for example, a motorconfigured to elevate the walls in a vertical direction.

Further, at least one of the first wall W₁ and second wall W₂ may beconfigured to be moved towards or relative to the press 144. It isimportant to note that the first wall W₁ and second wall W₂ are notparticularly limited in that any suitable mechanism form setting areference distance (or orienting an angle) between the support surface138 and the press 144 may be provided in place of the first wall W₁ andsecond wall W₂. See FIGS. 14A-14E.

Further, the “motorized wall” may be actuated by a piezo Z translator orby a motorized actuator. It is noted that in a case where the layer ispressed substantially with the support surface and the contact surfaceof the press being parallel to each other, some air bubbles mayaccumulate within the layer. See FIG. 14A. By initially applying thepressure at an angle and slowly (e.g., gradually or progressing)orienting the support surface and the contact surface of the press to beparallel to each other, air may be squeezed out of the layer.

In accordance with another feature, a method of solid free formfabrication may include providing a press 144 and a support assemblyhaving a support surface 138, a driver and a press stop PS. Further, thedriver may be configured to elevate and lower the support surface 138relative to the press stop PS. In addition, the method may includepositioning the support surface 138 such that a predetermined distanceis defined between a surface of the press stop PS, which is configuredto engage an abutment surface of the press 144, and a support surface138. Further, the method may include depositing a first material 136onto the support surface, bringing the surface of the press stop PS andthe abutment surface of the press 144 into contact with each other suchthat the first material 136 is pressed into a first material layerhaving a thickness corresponding to the predetermined thickness,separating the press stop PS and the abutment surface of the press 144from each other, and selectively ablating the first material layer 136to form vacant regions within the first material layer. See FIG. 11E.

A further feature may include dispensing at least a second material 150onto the first material layer to fill the vacant regions formed withinthe first material layer 136, and bringing the surface of the press stopPS and the abutment surface of the press 144 into contact with eachother such that the second material 150 is leveled. FIG. 11G. Also, whena thin residue layer of the second material 150 remains after the secondmaterial 150 is leveled, the residue layer may be ablated to remove atleast a portion of the residue layer. See FIG. 12A and 12C. Further, theentire residue layer may be removed by ablation. See FIG. 12A and 12B.In another feature of the present disclose, at least regions of theresidue layer immediately surrounding the second material that fills thevacant regions of the first material are removed. See FIG. 12C. Also,the method may include at least one of an upper surface of the firstmaterial layer and a leveled surface of the second material beingablated to provide a texturized surface to improve adhesion of asubsequent layer deposited on the texturized surface (e.g., as discussedin relation to FIG. 8G). Also, as a further feature, the first materialmay be at least partially cured. Further, in accordance with anotherfeature, at least one of the first material and the second material maybe partially cured. See FIG. 11D.

Further, any desired material layer may be comprised of multipledifferent materials (e.g., any number of different active materials andsupport materials) that may be determined, for example, based upon slicedata as discussed in the present disclosure. For example, multipledifferent materials may be dispensed from different dispensing headsbased upon the slice data in order to form a predetermined layer(s)comprising the multiple different materials. Such dispensing could takeplace concurrently or in any desire order depending upon the desiredapplication.

In yet another feature, a method of solid free form fabrication usingthe printer pressing assembly of the present disclosure may includeproviding the press strop PS with a first press stop PS₁ and a secondpress stop PS₂. See FIGS. 14A and 14B. Further, the method may includeelevating the first press stop PS₁ to a different height relative to thesecond press stop PS₂ so as to provide an inclined engagement surfacethat engages the abutment surface of the press 144 such that the press144 is oriented at angle with respect to the support surface 138. SeeFIG. 14C. Further, the method may include progressively lowering anelevation of one of the first press stop PS₁ and the second press PS₂stop such that the first material 136 is progressively pressed by thepress 144 in a direction from one end of the support surface towardsanother end of the support surface 138. FIG. 14C and 14D. Thereby,eliminating air bubbles within the first material as the contact surfaceof the press becomes oriented horizontal to the support surface. Forexample, by inclining and pressing the material, with the effects ofgravity, air bubbled can be prevented and eliminated within thematerial(s).

In addition, it should be noted that the “support surface” may be atable, substrate, prior layer of material, or any other surface on whichthe material may be directly or indirectly deposited. For example, thesupport surface may be a printed circuit board “PCB” on whichmaterial(s) may be deposited and ablated in accordance with aspects ofthe present disclosure. For example, a material layer may be depositedon a PCB and ablated according to, for example, slice-data to formvacant regions within the material layer to delimit or define anelectrically conductive pattern formed on the circuit board.

Further, in accordance with another feature, a solid free formfabrication system incorporating the printer pressing assembly of thepresent disclosure may include an ablation system (e.g., a pulse laser)configured to cure and ablate the material dispensed onto the supportsurface, and the curing and ablating is performed by the same ablationsystem, which is configured to operate at a different set of parameters.See FIGS. 16A-16C. Further, the ablation system may include a pulselaser configured to emit a laser beam at different intensities.

Further, in accordance with yet another feature of the presentdisclosure, a solid free form fabrication system incorporating theprinter pressing assembly may further include a curing member configuredto cure the material dispensed onto the support surface and an ablationsystem configured to ablate the material dispensed onto the supportsurface. See FIGS. 16A-16C. Further, the ablation system may include aComputer Numeric Controlled (CNC) system.

In another feature of the present disclosure, a system for solid freeform fabrication may include a material deposited on a surface, and alaser source configured to emit a laser beam at different setparameters. Further, the laser source, when emitting the laser beam at afirst setting of the different set parameters, may be configured to curethe material deposited on the surface. The laser source, when emittingthe laser beam at a second setting of the different set parameters, maybe configured to sinter the material deposited on the surface. The lasersource, when emitting the laser beam at a third setting of the differentset parameters, may be configured to ablate the material deposited onthe surface. Further, the laser source may include an ultraviolet fiberlaser. Further, a pulse duration of the laser may be adjusted in settingone of the first setting, the second setting and the third setting.Additionally, the pulse duration may be configured to be selected withina range of between 2-200 nanoseconds to perform a selected one ofcuring, sintering and ablating.

More particularly, when the laser source is provided as a ultraviolet(UV) laser fiber, it is possible to tune or adjust a number orparameters, e.g., a pulse width, a frequency, or an energy of the laserand (apply the laser source) without unintentionally damaging, e.g., adelicate or sensitive material (e.g., since the present laser source maybe provided as a UV laser).

Therefore, the UV laser source of the present disclosure may be utilizedin a multitude of free forming processes. For example, in a photo curingprocess, which may include the polymerization of an organic monomer, UVlight generally below 405 nm with quasi continuous emission may beutilized. For example, during a photo curing process the material may besubjected or exposed to a large pulse width of ˜200 ns at a relativelyhigh frequency of 700 kHz and an energy level lower than the energy thatwould heat the material. See FIG. 16.

Further, in a sintering process, in which partial ablation of thematerial may occur (or is desired), it is necessary for the material tosufficiently absorb the UV light, i.e., in order to enable heating ofthe material. Accordingly, since UV light is absorbed well by mostmaterials and a quasi-continuous emission is desired in the sinteringprocess, a large pulse width of ˜200 ns at high frequency of 700 kHz anda relative high level of energy to heat the materials may be provided.

Also, in an ablation process, in which the materials may be densified byexciting nano/micro particles within the material, light to heat thematerials and enable evaporation in a the shortest time possible toavoid heat deformation of the materials is needed. In general, since UVlight is absorbed well by most of materials, a short pulse emission isset in order to generating UV light suitable for the ablation process.For example, a short pulse width of ˜<2 ns at high frequency of 10 kHzwith and high energy level to evaporate the materials may be used. Thedensified material may be any in any one of a powder form, a metalcolloid, a ceramic colloid, a semiconductor particle ink colloid, apaste, etc.

Therefore, the same UV laser of the present disclosure may be used in atleast three distinct processes (namely curing, sintering, and ablating).

As used herein the term “about” may refer to ±10%. Throughout thisapplication, various embodiments of the present disclosure may bepresented in a range format. It should be understood that thedescription in range format is merely for convenience and brevity andshould not be construed as an inflexible limitation on the scope of thedisclosure. Accordingly, the description of a range should be consideredto have specifically disclosed all the possible subranges as well asindividual numerical values within that range. For example, descriptionof a range such as from 1 to 6 should be considered to have specificallydisclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numberswithin that range, for example, 1, 2, 3, 4, 5, and 6. This appliesregardless of the breadth of the range.

Whenever a numerical range is indicated herein, it is meant to includeany cited numeral (fractional or integral) within the indicated range.The phrases “ranging/ranges between” a first indicate number and asecond indicate number and “ranging/ranges from” a first indicate number“to” a second indicate number are used herein interchangeably and aremeant to include the first and second indicated numbers and all thefractional and integral numerals therebetween.

It is appreciated that certain features of the disclosure, which are,for clarity, described in the context of separate embodiments, may alsobe provided in combination in a single embodiment. Conversely, variousfeatures of the present disclosure, which are, for brevity, described inthe context of a single embodiment, may also be provided separately orin any suitable subcombination or as suitable in any other describedembodiment of the present disclosure. Certain features described in thecontext of various embodiments are not to be considered essentialfeatures of those embodiments, unless the embodiment is inoperativewithout those elements.

Various embodiments and aspects of the present disclosure as delineatedhereinabove and as claimed in the claims section below find support inthe following examples.

EXAMPLES

Reference is now made to the following examples, which together with theabove descriptions illustrate some embodiments of the present disclosurein a non limiting fashion.

Exemplified SFF Process

FIG. 6 is a flow chart diagram describing a representative example of anSFF process, according to some embodiments of the present disclosure. Alayer thickness is defined by vertical drive 94. Then, a material isdispensed, following by an optional drying operation. Stagnating is thenapplied, for example, by a blade squeegee. Thereafter, the leveled (orstraightened) material is ablated to form a two-dimensional pattern.Optionally, the material is then cured or sintered. An additionalstraightening operation can optionally executed following the curing orsintering. The process then loops to the first block for defining thenext layer.

Exemplied Placement of Foreign Element

FIG. 7 is a flow chart diagram describing a representative example of aprocess for combining a foreign element with a solid freeform fabricatedobject, according to some embodiments of the present disclosure. Cavity72 is abated in the dispensed building material. The foreign element ispicked from the array 110 and placed in the cavity 72. An additionallayer is then added, and a pattern for a conductive track is ablated. Aconductive building material is then dispensed to fill the ablatedpattern. Sintering, such as, but not limited to, laser sintering, isapplied to the conductive building material.

Although the disclosure has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

All publications, patents and patent applications mentioned in thisspecification are herein incorporated in their entirety by referenceinto the specification, to the same extent as if each individualpublication, patent or patent application was specifically andindividually indicated to be incorporated herein by reference. Inaddition, citation or identification of any reference in thisapplication shall not be construed as an admission that such referenceis available as prior art to the present disclosure. To the extent thatsection headings are used, they should not be construed as necessarilylimiting.

What is claimed is:
 1. A printer pressing assembly for forming materiallayers, the pressing assembly comprising: a support assembly having asupport surface, a driver and a press stop, wherein the driver isconfigured to change an elevation of the support surface relative to anelevation of the press stop; a nozzle configured to dispense a materialonto the support surface; and a press configured to be positionedopposite to the support surface and configured to move relative to thesupport, wherein the press stop is configured to be elevated above thesupport surface so as to engage an abutment surface of the press,thereby setting a pre-determined distance between a contact surface ofthe press and the support surface.
 2. The printer pressing assemblyaccording to claim 1, wherein the press stop comprises a wallsurrounding the support surface.
 3. The printer pressing assemblyaccording to claim 1, wherein the press stop comprises a plurality ofelongated stops.
 4. The printer pressing assembly according to claim 1,wherein the press has a plate-shaped surface provided with the contactsurface and configured to be positioned opposite to the support surface.5. The printer pressing assembly according to claim 1, wherein the presscomprises a roller configured to level a material deposited on thesupport surface by translating in a direction parallel to the supportsurface.
 6. The printer pressing assembly according to claim 5, whereinthe roller comprises a stationing rod and a movable rod, wherein thestationary rod engages at least a portion of the press stop and themovable rod translates in the direction parallel to the support surfaceso as to level the material deposited on the support surface.
 7. Theprinter pressing assembly according to claim 6, wherein a foil extendsaround outer peripheries of the stationing rod and the movable rod so asto come into direct engagement with the material deposited on thesupport surface as the movable rod translates in the direction parallelto the support surface.
 8. The printer pressing assembly according toclaim 7, wherein the foil extending around the outer periphery of themovable rod departs the movable rod so as to be oriented at an acuteangle with respect to the support surface.
 9. The printer pressingassembly according to claim 8, wherein a first end of the foil is woundaround a first spool and a second end of the foil is connected to asecond spool such that the foil is released from one of the first andsecond spools as the movable rod translates.
 10. The printer pressingassembly according to claim 1, further comprising a curing memberconfigured to cure the material deposited on the support surface. 11.The printer pressing assembly according to claim 1, further comprising alaser source configured to emit a laser beam so as to ablate thematerial deposited on the support surface.
 12. The printer pressingassembly according to claim 2, wherein the wall comprises a first walland a second wall.
 13. The printer pressing assembly according to claim12, wherein the first wall is configured to be elevated to a differentheight relative to the second wall so as to provide an inclinedengagement surface that engages the abutment surface of the press. 14.The printer pressing assembly according to claim 13, wherein at leastone of the first wall and second wall is configured to be moved towardsthe press.
 15. A method of solid free form fabrication, the methodcomprising: providing a press and a support assembly having a supportsurface, a driver and a press stop, the driver being configured toelevate and lower the support surface relative to the press stop,positioning the support surface such that a predetermined distance isdefined between a surface of the press stop, which is configured toengage an abutment surface of the press, and the support surface,depositing a first material onto the support surface, bringing thesurface of the press stop and the abutment surface of the press intocontact with each other such that the first material is pressed into afirst material layer having a thickness corresponding to thepredetermined thickness, separating the press stop and the abutmentsurface of the press from each other, and selectively ablating the firstmaterial layer to form vacant regions within the first material layer.16. The method according to claim 15, further comprising dispensing atleast a second material onto the first material layer to fill the vacantregions formed within the first material layer, and bringing the surfaceof the press stop and the abutment surface of the press into contactwith each other such that the second material is leveled.
 17. The methodaccording to claim 16, wherein, when a thin residue layer of the secondmaterial remains after the second material is leveled, the residue layeris ablated to remove at least a portion of the residue layer.
 18. Themethod according to claim 17, wherein the entire residue layer isremoved by ablation.
 19. The method according to claim 17, wherein atleast regions of the residue layer immediately surrounding the secondmaterial that fills the vacant regions of the first material areremoved.
 20. The method according to claim 16, wherein at least one ofan upper surface of the first material layer and a leveled surface ofthe second material is ablated to provide a texturized surface so as toimprove adhesion of a subsequent layer deposited on the texturizedsurface.
 21. The method according to claim 15, further comprising atleast partially curing the first material.
 22. The method according toclaim 16, further comprising at least partially curing at least one ofthe first material and the second material.
 23. A method of solid freeform fabrication using the printer pressing assembly according to claim1, further comprising: providing the press strop with a first press stopand a second press stop, elevating the first press stop to a differentheight relative to the second press stop so as to provide an inclinedengagement surface that engages the abutment surface of the press suchthat the press is oriented at angle with respect to the support surface,and progressively lowering an elevation of one of the first press stopand the second press stop such that the first material is progressivelypressed by the press in a direction from one end of the support surfacetowards another end of the support surface, thereby eliminating airbubbles within the first material as the contact surface of the pressbecomes oriented horizontal to the support surface.
 24. A solid freeform fabrication system incorporating the printer pressing assemblyaccording to claim 1, further comprising: an ablation system configuredto cure and ablate the material dispensed onto the support surface,wherein the curing and ablating is performed by the same ablationsystem, which is configured to operate at a different set of parameters.25. The solid free form fabrication system incorporating the printerpressing assembly according to claim 24, wherein the ablation systemcomprises a pulse laser configured to emit a laser beam at differentintensities.
 26. A solid free form fabrication system incorporating theprinter pressing assembly according to claim 1, further comprising: acuring member configured to cure the material dispensed onto the supportsurface; and an ablation system configured to ablate the materialdispensed onto the support surface.
 27. The solid free form fabricationsystem incorporating the printer pressing assembly according to claim26, wherein the ablation system comprises a Computer Numeric Controlled(CNC) system.